I would like to find a very simple addon to help my wife remember to cast her buffs. She is leveling a Priest, and could use a hand keeping up Inner Fire on herself as well as Power Word: Fortitude and Divine Spirit on the party.

I myself currently use ZOMGBuffs, but I want to look into other options before recommending one to her.

If she plans to do any healing, VuhDo has a lot of panels and options. One of these is the "BuffWatch", in which she can choose any buff and an indicator will show up here when it is missing from herself or a party member.

I have mine set to turn off all panels except BuffWatch when I'm not in a party.